There has existed a considerable problem, for example in agricultural spraying tasks, relating to use of various spray nozzles for selectively adjusting volume and spray pattern for various selected materials being dispensed. Different chemicals require different application rates and or spray patterns. Flow of the chemical may be controlled, at least in part, by changing the spray nozzle size. In conventional agricultural sprayers; in order to change the flow, it is necessary to remove and replace each of the many nozzles along the spray tube. This is a tedious process and involves a considerable amount of time and frustration. The small nozzles are relatively difficult to handle and, in adverse conditions, can easily be dropped and lost. Often, rather than change out the nozzles, a farmer will risk inaccurate application of chemicals, simply to save time and the frustration of repeatedly changing and re-changing the nozzles.
It therefore becomes desirable to obtain some form of device that will facilitate quick changing of spray nozzles without tedious disassembly and replacement of individual nozzles.
Various apparatus have been developed which including orifice selection capability. However, these apparatus are typically "in line" rather than at an end of a fluid line and so do not lend themselves for use as nozzle selectors. They also usually require relatively elaborate sealing procedures in order to prevent leakage of fluid from the vicinity of the orifice selection mechanism. Furthermore, many of these apparatus are relatively complex and may not be easily disassembled for cleaning or repair.
An example of a very useful flow selector device is disclosed in our U.S. Pat. No. 4,869,285. The device is used for placing a selected restriction in the form of a selected orifice in a single fluid flow line. The device makes use of a housing interrupting the fluid line. The housing includes an internal chamber in which an internal annular orifice plate is mounted, with a plurality of flow control orifices spaced about its perimeter. The plate is sealed within the housing. The internal orifice plate may be selectively rotated to bring any one of its orifices into alignment with the fluid passage through the housing. A clamping arrangement is also provided within the sealed housing to securely clamp the internal orifice plate between seals with the selected orifice in line with and completing the fluid flow line. The clamp device is also operable to release clamping pressure and allow selective rotation of the internal orifice plate to bring a selected orifice into alignment with the fluid line.
While our patented device functions well for flow control within a single flow line, the internal orifice plate and single discharge do not lend themselves to use for multiple discharge externally exposed nozzles. A need has therefor remained for a device that will eliminate the need to individually interchange multiple external exposed nozzles along a fluid supply line.